1. Field of the Invention
The present invention relates to a breathing protector for a laryngectomized or tracheotomized person with a stoma communicating with trachea, to be applied to the person""s neck covering the stoma. The person breathes fully or partially through the protector in order that moisture and heat shall be exchanged between exhaled air and inhaled air.
More particularly the invention relates to a breathing protector of the kind comprising a first opening for communication with the stoma; a second opening for communication with the surroundings; a flow path for respiration air between said first and second openings, and a heat-moisture exchanger body in said flow path.
2. Description of the Related Art
Protectors of the kind referred to are described in U.S. Pat. No. 3,920,009 (Olsen) and in U.S. Pat. No. 5,022,394 (Chemielinski). The devices disclosed therein function well as a heat-moisture exchanger the respiration air following a straight flow path through the exchanger body between the first and second openings. However, these prior art protectors are disadvantageous as said second opening communicating with the surroundings can easily be covered by a shirt, scarf, or the like, and when this happens, the flow of respiration air through the stoma will be obstructed, causing difficulty in breathing.
A breathing protector of the kind referred to herein which attempts to alleviate this problem is described in WO 95/17138 (Persson). The respiration air also in this case follows a straight path through the exchanger body between the first and second openings. The protector includes a movable spring biased cover plate that can be depressed against the surface of the heat-moisture exchanger body at said second opening to shut off the flow of air through said body, the respiration air then passes through a voice prosthesis located in the wall between trachea and esophagus of the user. When the cover plate valve is not depressed, the respiration air flows through the breathing protector at right angles to the said straight path through the exchanger body at said second opening. The device therefore can be worn beneath, for example, a shirt without the flow of air to and from the user being obstructed. However, this prior art breathing protector has the disadvantage of being of a relatively complicated structure and being relatively expensive to manufacture due to the complexity thereof. Moreover, the prior art breathing protector has a relatively large axial length.
SE-B-348 643 (Gibeck), GB-A-2 214 089 (Andersson et al), and GB-A-2 250 201 (Andersson et al) disclose breathing protectors of the kind referred to herein which at said second opening are provided with an element that deflects, in a transverse direction, the respiration air flowing along the straight path through the heat-moisture exchanger body, but also these breathing protectors suffer from disadvantages similar to those of the breathing protector disclosed in WO 95/17138.
The primary object of the present invention is to provide a breathing protector which eliminates the risk of blocking of the flow of air and which is simultaneously of a very simple and reliable construction.
To achieve this object the invention provides a breathing protector of the kind referred to herein further comprising a substantially flat surface formed by said body and facing the neck when the breathing protector is applied to the neck covering the stoma, said substantially flat surface being dimensioned to extend beyond the stoma to cover also a part of the neck surrounding the stoma, said second opening including at least one part a direction of which has at least one component which is substantially parallel with said substantially flat surface.
By this arrangement which does not increase the overall length of the breathing protector it is possible for the respiration air to flow through the breathing protector even if a shirt or the like covers the outer end, of the protector.
In a preferred embodiment all of said second opening has a direction which is substantially parallel with said substantially parallel with said substantially flat surface, making certain that none of the flowing air will be affected by any clothing that comes into contact with the breathing protector.
This embodiment can be accomplished in a simple way by providing on the heat-moisture exchanger body a flat end surface that is turned away from said substantially flat surface, and a plate covering the end surface. The plate also supports the heat-moisture exchanger body and prevents it from being contaminated by clothing that contacts the outside of the body.
Preferably, said second opening is fully open around the entire periphery of the heat-moisture exchanger body, thereby providing maximum usage of the available space and permitting the design of the breathing protector to be simplified as much as possible, thus making it simple and inexpensive to manufacture and simple for the patient to handle.
In certain cases, it may be appropriate to arrange a casing that houses the heat-moisture exchanger body. An opening is made in the casing for said at least one part of said second opening. The heat-moisture exchanger body will thus be better protected against external effects.
The breathing protector can comprise an attachment device for attaching the breathing protector to the skin of the person, and heat-moisture exchanger body can be removably attached to the attachment device. This is advantageous in that the heat-moisture exchanger body can be replaced without loosening the connection with the skin of the person. This makes the use of the breathing protector considerably more comfortable because loosening this connection can cause irritation and pain, especially if the attachment device comprises an attachment device. It is preferred that the connection between the heat-moisture exchanger body and the attachment film comprises an adhesive. This provides a design which is very simple as compared with some form of locking or snap-in device, thereby reducing manufacturing costs and making it very easy to replace the heat-moisture exchanger body.
In accordance with another preferred embodiment the heat-moisture exchanger body has an open structure with several flow passages randomly oriented therein, for example as in wadding or foamed plastic.
The breathing protector can have a valve function for shutting off or throttling air flow through said flow path. The heat-moisture exchanger body in that case is elastic in at least one direction perpendicular to said substantially flat surface. A socket projects at substantially right angle from the substantially flat surface and communicates with said first opening, the heat-moisture exchanger body forming a through hole in register with said first opening and receiving the socket therein. The socket extends over part of the length of the hole, and the plate which can be engaged with an annular end surface of the socket under compression of the heat-moisture exchanger body against the substantially flat surface, corresponding to a closed condition of the valve function, the heat-moisture exchanger body biasing the plate to a position spaced from said annular end surface, corresponding to an open condition of the valve function.
The invention will be explained in more detail with reference to the accompanying drawings.